Apparatus for use with a natural gas dehydrator

ABSTRACT

Apparatus for use with a natural gas dehydrator wherein a portion of the wet glycol in an emissions separator is pumped under pressure as circulating wet glycol which may be used as a coolant for effluent removed from a reboiler and/or a power source for an eductor to form a vacuum in a first chamber of a liquid water removal separator apparatus. The cooled effluent, comprising at least liquid water, liquid hydrocarbons and uncondensed vapors, moves into the first chamber wherein the liquid water and/or the liquid hydrocarbons are separated from the uncondensed vapors. At least, the uncondensed vapors are removed from the first chamber and move into the eductor wherein they are compressed and combined into the circulating wet glycol. The separated liquid water is transferred to a second chamber of the liquid water removal separator apparatus and then removed therefrom. In some instances, the liquid hydrocarbons are transferred to a third chamber and removed therefrom. Apparatus is also provided to remove liquid hydrocarbons from the emissions separator. Also, gases from gas emitting level control apparatus are collected and fed into the first chamber.

This application is a continuation application of U.S. patentapplication Ser. No. 09/565,885 filed May 5, 2000, now U.S. Pat. No.6,364,933, of Rodney T. Heath for Apparatus For Use With A Natural GasDehydrator, which is a continuation-in-part application of U.S. patentapplication Ser. No. 09/333,115 filed Jun. 15, 1999, now U.S. Pat. No.6,238,461, of Rodney T. Heath for Natural Gas Dehydrator, both of whichare hereby incorporated by reference for all that is disclosed therein.

FIELD OF THE INVENTION

This invention relates generally to apparatus for use with natural gasdehydrators of the type used to remove water and water vapor from anatural gas stream composed of a mixture of natural gas, liquidhydrocarbons, liquid hydrocarbon vapors, water and water vapors and isparticularly directed to apparatus for use with field natural gasdehydrators.

BACKGROUND OF THE INVENTION

An example of such a field natural gas dehydrator is disclosed in U.S.Pat. No. 5,766,313 to Rodney Thomas Heath and the disclosure therein isspecifically incorporated herein by reference thereto. In general, suchsystems comprise a separator means for receiving the oil and waterliquids from “wet” (water vapor laden) gas; and a water absorber means,which employs a liquid dehydrating agent such as glycol, for removingthe water vapor from the wet gas and producing “dry” gas suitable forcommercial usage. The glycol is continuously supplied by a pump to theabsorber means in a “dry” low-water vapor-pressure condition and isremoved from the absorber means in a “wet” high-water vapor-pressurecondition. The wet glycol is continuously removed from the absorbermeans and circulated through a reboiler means, which includes a stillcolumn, for removing the absorbed water from the glycol and heating theglycol to provide a new supply of hot dry glycol. Heating of the glycolin the reboiler means is generally accomplished through use of a gasburner mounted in a fire tube. The hot dry glycol from the reboilermeans passes through a heat exchanger, where the hot dry glycoltransfers some of its heat to incoming wet glycol going to the stillcolumn. The dry glycol subsequently passes to a dry glycol storage tank.A glycol passage means is provided to enable passage of wet glycol fromthe absorber means to the reboiler means and to pump dry glycol from thestorage tank to the absorber means. Besides water, the wet glycol goingto the still column of the reboiler of the natural gas dehydrator willcontain natural gas and absorbed hydrocarbons.

On many dehydrators, a volume of natural gas is intentionally inducedinto the reboiler in order to dry the wet glycol to a higherconcentration than can be accomplished by simply adding heat. Theprocess of intentionally inducing a volume of natural gas into thereboiler is referred to as gas stripping.

In the still column of the reboiler of the natural gas dehydrator, thewater, natural gas, and other hydrocarbons are separated from the glycolby the pressure reduction from the absorber pressure to approximatelyatmospheric pressure in the still column and by the application of heatfrom the burner in the fire tube of the reboiler.

The water, natural gas, and other hydrocarbons contained in the wetglycol stream which are separated in the still column from the wetglycol will be exhausted into the atmosphere through the atmosphericvent on the still column. The hydrocarbon vapors released through thestill column of a natural gas dehydrator are air pollutants.Specifically, certain hydrocarbons such as benzene, toluene,ethylbenzene, and xylene, commonly referred to as BTEX have been provento be carcinogenic.

The gas dehydrator disclosed in U.S. Pat. No. 5,766,313 offers solutionsto at least some of the problems discussed above but improvements can bemade to such a gas dehydrator.

BRIEF DESCRIPTION OF THE INVENTION

This invention provides apparatus for use with a field natural gasdehydrator in which the wet glycol from the absorber is fed into a threephase emissions separator apparatus which is provided with suitableapparatus, such as an overflow tank, that contains an amount of wetglycol, part of which is used as a circulating medium as described morefully below, and routes another part of the wet glycol, such as anamount equal to the amount of wet glycol received from the absorber, toa reboiler. In the description of the invention, the apparatus isdescribed in its operating condition. The circulating wet glycol is usedto cool the emissions from the still column of a reboiler and to providethe energy to create a vacuum using an eductor as described more fullybelow. By using the part of the wet glycol as the pump circulatingmedium, the lubricity, vapor pressure, viscosity, and etc. of thecirculating medium remain relatively constant from dehydrator todehydrator; therefore overcoming potential pump problems which couldoccur if a circulating medium with changing physical constants, fromdehydrator to dehydrator, was used.

Also, the wet glycol can be pumped in greater volumes and used as a heatexchange medium for condensing the effluent from the still column of thereboiler. As explained more fully below, the volume of the wet glycolbeing pumped by the circulating pump is 20 to 30 times greater than thevolume of the wet glycol exiting the absorber.

In one embodiment, this invention also provides a liquid water separatorand removal apparatus that collects the liquid water condensed from theeffluent from the still column so that substantially no water in theform of vaporized water or liquid water is returned into the emissionsseparator. Ideally, substantially all of the water in the vaporizedwater in the effluent is changed into liquid water in an effluentcondenser apparatus and is fed into and removed in the liquid waterseparator and removal apparatus. This is accomplished in the instantinvention by cooling the effluent to a temperature in the effluentcondenser that condenses substantially all of the vaporized water andeven some of the vaporized hydrocarbons to produce liquid hydrocarbons.

The invention also provides a system for collecting the gases from thelevel controllers used in the natural gas dehydrator so that thecollected gases may be used as fuel for the burner of the reboiler.

In accordance with one embodiment of this invention, a natural gasdehydrator is provided wherein a supply of natural gas is fed into anabsorber wherein it is subjected to dry glycol to remove undesirablematerials therefrom so that the dry glycol is changed into wet glycolthat is removed from the absorber and fed at reduced pressure into afirst separator comprising a three phase emissions separator apparatus.When the invention is under operating conditions, the three phaseemissions separator apparatus has liquid level control apparatus thatprovides for holding a predetermined amount of wet glycol some of whichis to be circulated as described below and some of which wet glycol thatis transferred to the still column of a reboiler apparatus that receivesthe wet glycol and changes such amount of wet glycol into dry glycol andvaporized effluent. Under operating conditions, the amount of wet glycolbeing transferred to the reboiler is substantially equal to the amountof wet glycol being fed into the three phase emissions separatorapparatus from the absorber. An effluent condenser apparatus is providedfor receiving the vaporized effluent. The effluent condenser apparatuscomprises a hollow shell having a tube extending therethrough whereinthe tube has an external spiral fin. The hollow shell has an inlet andan outlet so that the wet glycol can be circulated therethrough. Theeffluent from the still column is fed into the tube and is cooled by thecirculating wet glycol. Circulating apparatus is provided forcirculating wet glycol from the three phase emissions separatorapparatus through the effluent condenser apparatus to change thevaporized effluent to at least liquid water, liquid hydrocarbons anduncondensed vapors, which are substantially hydrocarbon vapors, andreturning the circulating wet glycol with other ingredients entrainedtherein to the three phase emissions separator apparatus. Secondseparator apparatus comprising liquid water separator and removalapparatus is provided for receiving the at least liquid water, liquidhydrocarbons and uncondensed vapors for separating and removing theliquid water. Additional apparatus is provided for removing the liquidhydrocarbons and the uncondensed vapors from the liquid water separatorand removal apparatus and feeding the liquid hydrocarbons and theuncondensed vapors to the three phase emissions separator apparatus.

The additional apparatus comprises an eductor having an inlet port, anexit port and a vacuum port. A first conduit through which thecirculating wet glycol flows is connected to the inlet port. A secondconduit extends between the outlet port and the three phase emissionsseparator apparatus. A third conduit extends between the liquid waterseparator and removal apparatus and the vacuum port of the eductor toform at least a relative vacuum in the liquid water separator andremoval apparatus.

The liquid water separator and removal apparatus comprises a hollowshell having a partition therein for forming at least a first and asecond chamber in the hollow shell. A first outlet port is formed in thefirst chamber and is connected to the third conduit so that a vacuum isformed in the first chamber. A first inlet port is formed in the firstchamber so that the at least liquid water, liquid hydrocarbons anduncondensed vapors from the condenser apparatus can flow into the firstchamber and be separated into at least an upper layer comprising theuncondensed vapors, a middle layer comprising the liquid hydrocarbonsand a lower layer comprising the liquid water. The first outlet port islocated so that the uncondensed vapors and the liquid hydrocarbons canflow through the first outlet port into the third conduit. The withdrawnuncondensed vapors and the liquid hydrocarbons enter the eductor and arecompressed and entrained into the wet glycol and flow with the wetglycol from the eductor to the three phase emissions separator. A secondoutlet port is formed in the first chamber and a second inlet port isformed in the second chamber. A conduit connects the second outlet portand the second inlet port so that the liquid water can flow from thefirst chamber into the second chamber. A drain port is formed in thesecond chamber for draining liquid water from the second chamber.

The natural gas dehydrator has at least one gas emitting level controlapparatus. Each of the three phase emissions separator apparatus and theliquid water separator and removal apparatus has a gas emitting levelcontrol apparatus. A gas inlet port is formed in the liquid waterseparator and removal apparatus. Collecting apparatus is provided forcollecting the gases emitted from the gas emitting level controlapparatus and conduits extend between the collecting apparatus and thegas inlet port for transmitting the gases to the gas inlet port.

In the operation of the above-described apparatus a supply of naturalgas is fed into an absorber wherein it is subjected to dry glycol toremove undesirable materials therefrom so that the dry glycol is changedinto wet glycol that is removed from the absorber and is processed byfeeding the wet glycol from the absorber into the three phase emissionsseparator apparatus; retaining a supply of wet glycol to a predeterminedlevel in the three phase emissions separator apparatus; feeding wetglycol greater than the predetermined level from the three phaseemissions separator apparatus to the still column of a reboiler forchanging such wet glycol into dry glycol and vaporized effluent; feedingthe vaporized effluent to a condenser apparatus; circulating wet glycolinto and out of the retained wet glycol in the three phase emissionsseparator apparatus so that wet glycol flows through the condenserapparatus to change the vaporized effluent to at least liquid water,liquid hydrocarbons and uncondensed vapors and returns the circulatingwet glycol with other added materials to the three phase emissionsseparator apparatus; feeding the at least liquid water, liquidhydrocarbons and uncondensed vapors to a liquid water separator andremoval apparatus; separating and removing the liquid water from the atleast liquid water, liquid hydrocarbons and uncondensed vapors; drainingthe removed liquid water; and entraining the at least liquidhydrocarbons and the uncondensed vapors into the circulating wet glycolto be returned to the three phase emissions separator apparatus.

A vacuum is formed in the liquid water separator and removal apparatusby positioning an eductor having an inlet port, an outlet port and avacuum port between the liquid water separator and removal apparatus andthe three phase emissions separator apparatus; feeding the circulatingwet glycol to the inlet port; passing the circulating wet glycol throughthe eductor and out of the outlet port to create a vacuum to draw theuncondensed vapors and liquid hydrocarbons from the liquid waterseparator and removal apparatus; compressing the uncondensed vapors andentraining them with any liquid hydrocarbons into the circulating wetglycol; and feeding the circulating wet glycol with the entrainedcondensed vapors and liquid hydrocarbons from the outlet port into thethree phase emissions separator apparatus.

The removal of the liquid water is accomplished by forming a first and asecond chamber in the liquid water separator and removal apparatus;feeding the at least liquid water, liquid hydrocarbons and uncondensedvapors into the first chamber; separating the at least liquid water, theliquid hydrocarbons and uncondensed vapors in the first chamber;removing the liquid hydrocarbons and the uncondensed vapors from thefirst chamber; entraining the removed uncondensed vapors and liquidhydrocarbons into the wet glycol in the eductor; transferring at least aportion of the liquid water from the first chamber to the second chamberuntil the liquid water in the second chamber reaches a predeterminedlevel; and removing at least a portion of the liquid water from thesecond chamber.

Additional gas is transferred to the first chamber by providing at leastone gas emitting level control apparatus in at least the absorber, thethree phase emissions separator apparatus and the liquid water separatorand removal apparatus; collecting the gases emitted by the gas emittinglevel control apparatus; and feeding the collected gases into the firstchamber.

In another embodiment of the effluent condenser apparatus, the finnedtube is connected to the effluent piping carrying the effluent issuingfrom the still column and is located within the hollow shell asdescribed above. Also, the hollow shell has longitudinally extendingexternal fins. The modified effluent condenser apparatus is locatedwithin a hollow tube having a diameter greater than the external fins ofthe hollow shell. The hollow tube has an enlarged cross section at oneend wherein a fan is located to blow air over the finned hollow shell.Also, a portion of the tubing through which the cooled effluent passesis exposed to the air. A thermostat is located in the piping or linecarrying the cooled effluent comprising hydrocarbon gas, liquidhydrocarbon, water and water vapors from the effluent condenserapparatus to the liquid separator and removal apparatus. The fan isturned on or off in response to the temperature in the cooled effluentas described below.

In a further embodiment of the effluent condenser apparatus, the wetglycol is not passed through the hollow shell. In this embodiment, onlythe finned tubing is located within the hollow tube having the fanlocated therein. A thermostat is also located in the line carrying thecooled effluent from the effluent condenser to the liquid separator andremoval apparatus and turns the fan on or off in response to the sensedtemperature.

In another embodiment of the invention, a two phase emission separatorapparatus is used instead of the three phase emission separatorapparatus and such two phase emission separator apparatus is describedmore fully below.

In another embodiment of the invention, a modified liquid separator andremoval apparatus acts on the cooled effluent to separate and removeboth the liquid water and the liquid hydrocarbons from the cooledeffluent leaving at least uncondensed hydrocarbon gases which are drawnfrom the liquid separator and removal apparatus by the vacuum formed bythe eductor as described above.

This modified liquid separator and removal apparatus comprises a hollowshell having two sealed partitions therein for dividing the hollow shellinto first, second and third chambers. The first chamber receives thecooled effluent comprising at least liquid water, liquid hydrocarbonsand uncondensed vapors. The first chamber has a first outlet portthrough which the uncondensed vapors, having at least hydrocarbon gases,are drawn into the eductor by the vacuum therein. A second outlet portin the first chamber removes the liquid hydrocarbons from the firstchamber and deposits the liquid hydrocarbons in the second chamber fromwhich they are removed as described below. A third outlet port in thefirst chamber removes the liquid water from the first chamber anddeposits the liquid water into the third chamber from which they areremoved as described below.

The invention also provides a heat exchanger for heating the wet glycolflowing from the two or three phase emission separator. Wet glycol ismoved from the two or three phase emission separator through a heatexchanger coil within the storage tank for the hot dry glycol receivedfrom the reboiler whereby the temperature of such wet glycol is raised.This higher temperature processed wet glycol is then passed through anouter shell of a heat exchanger which has a finned tubing encasedtherein. The circulating wet glycol from the two or three phaseemissions separator apparatus passes through the finned tubing so thatthe temperature of the circulating wet glycol therein is raised. Thepassage of the circulating wet glycol through the finned tubing in theheat exchanger is controlled by a thermostat associated with the two orthree phase emissions separator apparatus.

The operation of the invention using the wet glycol heat exchanger, theeffluent condenser apparatus wherein the wet glycol is used to treat theeffluent from the still column and the modified liquid separator andremoval apparatus is as follows. The effluent issuing from the stillcolumn is fed into the finned tubing in the effluent condenserapparatus. The wet glycol flows in the hollow shell around the hoteffluent in the finned tubing to produce a treated effluent comprisingat least liquid hydrocarbons, liquid water and uncondensed vaporscontaining at least gaseous hydrocarbons all of which pass out of theeffluent condenser apparatus and into the modified liquid separator andremoval apparatus. The thermostat senses the temperature of thecirculating wet glycol and determines whether or not the circulating wetglycol from the emissions separator apparatus is or is not to be passedthrough the heat exchanger by the operation of a valve controlled by thethermostat. When the valve is fully closed, the circulating wet glycolis fed to the effluent condenser apparatus. When the valve is fullyopen, the circulating wet glycol is fed through the heat exchanger andthe liquid separator and removal apparatus to the eductor. As the valvemoves between the fully opened and fully closed positions, the amount ofthe circulating wet glycol passed through the heat exchanger isproportionally changed. In some instances, it may be necessary to usethe fan to further cool the effluent passing through the pipe in theeffluent condenser apparatus. The treated effluent enters the firstchamber of the modified liquid separator and removal apparatus whereinthe uncondensed vapors are removed by the vacuum in the eductor; theliquid hydrocarbons are removed from the first chamber to the secondchamber and the liquid water is removed from the first chamber to thethird chamber. When the liquid hydrocarbons in the second chamber reacha predetermined level, at least a portion of the liquid hydrocarbons inthe second chamber are removed therefrom. When the liquid water in thethird chamber reaches a predetermined level, at least a portion of theliquid water is removed therefrom. The circulating wet glycol passesthrough the eductor to create the above-described vacuum and theuncondensed vapors from the modified liquid separator and removalapparatus are compressed and entrained in the circulating wet glycol andthen pass into the emissions separator apparatus.

The operation of the invention not using the circulating wet glycol inthe effluent condenser apparatus but using the heat exchanger and themodified liquid separator and removal apparatus is as follows. The hoteffluent from the still column flows into the finned tubing in theeffluent condenser apparatus. A fan, controlled by another thermostat,operates to cool the hot effluent to produce at least liquidhydrocarbons, liquid water and uncondensed vapors containing at leastgaseous hydrocarbons. If the outside temperature is low enough, it isgenerally not necessary to operate the fan to cool the hot effluent.Also, the thermostat in the emissions separator apparatus or tubing orpiping functions to determine whether or not the circulating wet glycolfrom the emissions separator apparatus is passed through the heatexchanger. When the valve is fully closed, the circulating wet glycol isfed through a heated coil in the liquid separator and removal apparatusand then to the eductor. When the valve is fully opened, the circulatingwet glycol is fed through the heat exchanger and then directly to theeductor. The treated effluent flows into the modified liquid separatorand removal apparatus and is processed thereafter as described above.

In another embodiment of the invention, prevention apparatus is providedto prevent the inadvertent transfer of liquid hydrocarbons to thereboiler and in particular from the two phase emissions separatorapparatus. The build up of liquid hydrocarbons in a two or three phaseemissions separator apparatus can result from the liquid hydrocarbons inthe wet glycol from the absorber, the carryover from the liquidseparator and removal apparatus and the further condensation of thehydrocarbon gases in the two or three phase emissions separatorapparatus. The prevention apparatus is described preferably in relationto a two phase emissions separator apparatus and comprises a throttlingliquid level control apparatus that is set to control the level of thetotal liquids in the emissions separator apparatus which total levelcomprises liquid hydrocarbons and wet glycol. A float that is weightedto float on top of the wet glycol is connected to apparatus for openingor closing a solenoid valve for purposes described below. A casinghaving a closed lower end and an open upper end is located at a presetlocation in the emissions separator apparatus. A pipe having an openbottom end is located within the casing and its open bottom is locatedabout one inch from the closed lower end and has its other open top endconnected to the solenoid valve. The emissions separator apparatus has alower level of wet glycol, an intermediate level of liquid hydrocarbonsand an upper level of gaseous hydrocarbons. An open ended tube has itsupper open end located in the emissions separator apparatus so that itis in the gaseous hydrocarbon level and its lower open end locatedadjacent to but spaced from the bottom of the emissions separatorapparatus so that it is located in the wet glycol level. An open endedpipe has a portion thereof located in the open ended tube so that itslower open end is located to be exposed under normal conditions to thewet glycol. The upper open end of the open ended pipe is secured to adumping apparatus for transferring wet glycol from the emissionsseparator apparatus to the still column.

In the operation of the prevention apparatus, when there is only arelatively small amount of liquid hydrocarbons in the emissionsseparator apparatus, the float on the wet glycol will close the solenoidvalve and the throttling liquid level apparatus will operate to dump wetglycol to the still column of the reboiler as the wet glycol from theabsorber enters the emissions separator apparatus. When the level of theliquid hydrocarbons reaches a predetermined amount, the level of the wetglycol will reach a lower level at which time the float will open thesolenoid valve so that the liquid hydrocarbons will flow through thesolenoid valve since the emissions separator apparatus is at a pressurehigher than atmospheric. This causes a drop in the total liquid level inthe emissions separator apparatus so that the throttling liquid levelcontrol apparatus shuts off the dumping apparatus so that no wet glycolis transferred to the still column of the reboiler. Since the wet glycolfrom the absorber continues to enter the emissions separator apparatus,the level of the wet glycol will start to rise in the emissionsseparator apparatus. Since the liquid hydrocarbons are dumped at a rategreater than the rate of entry into the emissions separator apparatus ofthe wet glycol from the absorber, a substantial amount of the liquidhydrocarbons will be dumped before the level of the wet glycol in theemissions separator apparatus raises the weighted float to a level toclose the solenoid valve. When the total level of liquid hydrocarbonsand wet glycol is detected by the throttling liquid level controlapparatus, wet glycol from the emissions separator apparatus will againbe dumped to the reboiler.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are illustrated in the drawingsin which:

FIG. 1 is a block diagram of the invention;

FIG. 2 is a schematic elevational view of the liquid water separator andremoval apparatus;

FIG. 3 is a schematic elevational view similar to FIG. 2 with partsremoved;

FIG. 4 is a schematic end elevational view of parts of FIG. 3;

FIG. 5 is a schematic end elevational view taken from the right side ofFIG. 2;

FIG. 6 is a schematic elevational view of another embodiment of aneffluent condenser of this invention;

FIG. 7 is a schematic elevational view of yet another embodiment of aneffluent condenser of this invention;

FIG. 8 is a schematic elevational view of another embodiment of a gasand liquid separator and removal apparatus of this invention;

FIG. 9 is a schematic cross-sectional illustration of a portion of FIG.8;

FIG. 10 is a schematic elevational view of a two phase emissionseparator of this invention;

FIG. 11 is a schematic elevational view of a wet glycol heat exchangerof this invention;

FIG. 12 is a block diagram of the operation of a wet glycol heatexchanger of FIG. 11;

FIG. 13 is a block diagram illustrating the operation of this inventionusing the effluent condenser of FIG. 6;

FIG. 14 is a block diagram illustrating the operation of this inventionusing the effluent condenser of FIG. 7;

FIG. 15 is a schematic side elevational view of apparatus forcontrolling the amount of liquid hydrocarbons in the system just as theliquid hydrocarbons are to be dumped;

FIG. 16 is similar to FIG. 15 but shows the emissions separatorapparatus when containing no liquid hydrocarbons; and

FIG. 17 is similar to FIG. 15 but shows the apparatus after at leastsome of the liquid hydrocarbons have been dumped.

DETAILED DESCRIPTION OF THE INVENTION

This invention is directed toward apparatus for use with a field naturalgas dehydrator such as the one described in U.S. Pat. No. 5,766,313, thedisclosure of which is specifically incorporated herein by referencethereto. The volume and pressure of the natural gas flowing through thesystem can vary in wide ranges. Each unit is designed by those skilledin the art to perform at wide ranges of volume and pressure of thenatural gas being processed and various controls have been associatedwith the natural gas dehydrators so that these dehydrators can beoperated in a conventional manner by those skilled in the art. Theoperation of the various portions of this invention uses suchconventional apparatus that are normally used in the operation of anatural gas dehydrator. Therefore, the specific parameters associatedwith the operation of the various components of this invention areparameters known by those skilled in the art. Some parameters are given.In accordance with this invention, the natural gas is first passedthrough a conventional three phase inlet separator (not shown) to removewater and liquid hydrocarbons therefrom. The natural gas is then fedinto an absorber 2, FIG. 1, through an inlet 4 so that the natural gascan flow upwardly through the absorber. Dry glycol is introduced throughinlet 6 and flows through spaced apart bubble trays (not shown) into theabsorber and then downwardly through the absorber. The dry glycolfunctions primarily to remove water from the natural gas and becomes wetglycol. The treated natural gas exits through outlet 8 in the topportion of the absorber 2 and is passed through a glycol-gas heatexchanger 10 and passes out as dry salable natural gas at relativelyhigh pressures, for example of 50 PSIG to 1500 PSIG depending on theoperating pressures of the pipeline system.

The wet glycol is collected in a wet glycol sump 12 in the bottomportion of the absorber 2 and flows under control to the inlet port 14of a conventional three phase emissions separator apparatus 16. Freegaseous hydrocarbons contained in the wet glycol will be released in thethree phase emissions separator as a result of the reduction of pressurefrom the pressure of the absorber of between about 50 and 1500 PSIG tothe pressure in the three phase emissions separator which is betweenabout 10 and 15 PSIG and preferably about 15 PSIG. This is accomplishedby conventional apparatus. Liquid hydrocarbons are separated from thewet glycol in the three phase emissions separator apparatus 16 by a weirsystem and are withdrawn through outlet 18. The wet glycol is collectedin one part of the three phase emissions separator apparatus 16 to apredetermined level and then the processed wet glycol flows to anotherpart of the three phase emissions separator. The flow of the wet glycolfrom the absorber to the three phase emissions separator is controlledby the amount of dry glycol required to remove the water vapor from thenatural gas being processed. The amount of dry glycol used is in therange of 3 to 6 gallons of dry glycol for each pound of water removed.The amount of dry glycol used is determined in a conventional manner.

The freed gaseous hydrocarbons exit through outlet 20 in the top portionof the three phase emissions separator apparatus 16 and flow throughconduit 21 into a system 22 as described in the '313 patent to be usedas fuel in a reboiler 24 as described more fully below.

Once the predetermined level of wet glycol has been reached in the threephase emissions separator apparatus 16, any additional amount of wetglycol such as that from the absorber 2 may be mixed with thepredetermined level of wet glycol and the same additional amount of wetglycol passes under control from the three phase emissions separatorapparatus 16 through pipe 26 and then through a coil 27 in the dryglycol storage 28 and then through pipe 29 to the still column 30 of thereboiler 24 wherein the wet glycol is changed into hot dry glycol whichis then fed through line 32 into the dry glycol storage 28. The coil 27functions as a heat exchanger to raise the temperature of the wet glycolpassing through the coil 27. The effluent from the still column, liquidwater, liquid hydrocarbons, vaporized water, gases and vaporizedhydrocarbons are processed as described more fully below.

Wet glycol is withdrawn from the predetermined level of wet glycol inthe three phase emissions separator apparatus 16 through outlet 34 andenters a pump 36 which circulates the wet glycol through transmissionlines into an effluent condenser 42.

In one example, the pump 36 feeds wet glycol into the line 35 at apreferable rate of at least 20 gallons per minute and at a preferablepressure of at least about 50 PSIG or greater to provide a sufficientflow of wet glycol through an eductor (described below) and to provideside stream filtration of any wet glycol not required to power theeductor. At point 37, the line 35 is divided into transmission line 38and a side stream line 39 which carries any excess circulating wetglycol to a particulate filter 40. A manually adjustable valve 41controls the flow of wet glycol through the particulate filter 40 sothat cleaned wet glycol flows into the emissions separator apparatus 16.A valve (not shown) in line 39 permits the closing of line 39 so thatthe particulate filter 40 may be changed as necessary. The pump 36 andthe adjustable valve 41 ensure that sufficient wet glycol is beingcirculated through line 38 to operate the eductor so that only excesscirculating wet glycol flows through the particulate filter 40.

The effluent condensor 42 comprises a hollow shell 43 having a finnedtubing 45 located therein. The effluent from the still column 30 flowsthrough piping 46 and enter into the finned tubing 45. The wet glycolenters at one end 44 of the effluent condensor 42 and flows around thefinned tubing 45. The wet glycol functions to cool the effluent in thefinned tubing 45. Using the wet glycol circulating as described abovegreatly increases the cooling efficiency of the effluent condensor 42.The amount of wet glycol circulating through the condenser system issubstantially greater than the amount of wet glycol exiting from theabsorber 2 and is about 20 to 30 times greater than the amount of wetglycol exiting from the absorber 2. The wet glycol then flows throughoutlet 48 of the effluent condensor 42 through suitable piping and flowsthrough a conduit 49 in a liquid water separator and removal apparatus50 and through line 51 into the power inlet port of a conventionaleductor 52 for creating a vacuum source that forms a vacuum in theliquid water separator and removal apparatus 50 for purposes describedmore fully below. The wet glycol flows out of the eductor 52 and,together with entrained other materials as described below, is passedinto the three phase emissions separator apparatus 16 through line 54.

The cooled effluent flows out of the effluent condenser 42 through line60 and enters the liquid water separator and removal apparatus 50wherein water is removed, as described below, through drain 62. Thesystem for removing the water is discussed more fully below. Hydrocarbonvapors and any unseparated liquid water and liquid hydrocarbons aredrawn out of the liquid water separator and removal apparatus 50 by thevacuum in the eductor 52 through line 64 and enter into the eductor andare entrained and compressed into the wet glycol passing through theeductor and move with the wet glycol into the three phase emissionsseparator apparatus 16 through line 54. The hydrocarbon vapors in thethree phase emissions separator apparatus 16 flow out thereof, asdescribed above, the wet glycol flows into the still column, asdescribed above, or is used to maintain the predetermined level of wetglycol in the three phase emissions separator apparatus 16. If anyliquid hydrocarbon is formed in the three phase emissions separatorapparatus 16, it is removed therefrom through outlet 18.

The dry glycol for the absorber 2 is drawn from the dry glycol storage28 through line 64 and flows through the glycol gas heat exchanger 10and enters an electric pump 66 or equivalent to enter the absorber 2through inlet 6.

The hydrocarbon vapors leaving the three phase emissions separator arefed into a system 22 wherein the hydrocarbon vapors alone or inconjunction with a supplemental fuel source are used to fire the burner68 in the reboiler. The wet glycol entering the still column of thereboiler is dried and exits from the reboiler into a dry glycol storagetank through line 32. This system 22 is similar to that disclosed inU.S. Pat. No. 5,766,313.

The absorber 2 has a level control apparatus 70, the emissions separatorapparatus 16 has two level control apparatus 72 and 74 and the liquidwater separator and removal apparatus 50 has a level control apparatus76. Each of the level control apparatus 70, 72, 74 and 76 emit a gasduring operation and are of the type marketed by Wellmark Company orKimray under the trade designation liquid level control. The emittedgases are collected from each level control apparatus and are fedthrough inlet port 140 into the chamber 106 (FIG. 3) of the liquid waterseparator and removal apparatus 102, illustrated as 50 in FIG. 1. Thegas from level control apparatus 70 is fed through conduit 78; the gasfrom level control apparatus 72 and 74 are fed through conduit 80 andthe gas from level control apparatus 76 is fed through conduit 82 to theinlet port 140. Eventually, these gases flow with the wet glycol fromthe eductor 52 into and then from the three phase emissions separatorapparatus 16 through conduit 21 to the system 22 to be used as fuel forthe burner 68.

The water removing system is illustrated in FIGS. 2-5. The cooling ofthe effluent in the effluent condenser 42 changes the effluent fromwater vapor to liquid water and hydrocarbon vapors to liquidhydrocarbons and some uncondensed vapors. The uncondensed vapors, theliquid water and liquid hydrocarbons flow under a slight vacuum in theliquid water separator and removal apparatus 50 (2 to 3 inches watercolumn) from the effluent condenser 42 through conduit 60 to the inlet100 of the liquid water separator and removal apparatus 102 (the same as50 in FIG. 1). The liquid water separator and removal apparatus 102 liesgenerally in a horizontal plane and has a generally cylindrical interiorand has a sealed baffle 104 to divide the liquid water separator andremoval apparatus 102 into two chambers 106 and 108. The chamber 106 hasa generally vertically extending pipe 110 which is open at the top 112and bottom 114. The pipe 110 has an open port 116 located approximatelyone inch below the outlet 118 of the liquid-water separator and removalapparatus 102. Open port 116 is connected by pipe 120 to outlet pipe 122in the shell 124 of the liquid water separator and removal apparatus102. The chamber 108 has an inlet port 126, a liquid water controlconnection 128, a liquid water outlet port 130 and a pressure supplyport 132.

The effluent from the effluent condenser 42 enters into the chamber 106at the same absolute pressure as leaving the effluent condenser 42. Theliquid hydrocarbons, gaseous hydrocarbons, uncondensed water vapor andany unseparated liquid water flow out of the chamber 106 through outlet118 and through line 64 (FIG. 1) to the vacuum port 134 of the eductor52 where they are entrained and compressed into the wet glycol flowingthrough the eductor 52. As described above, it is desirable to condensepractically all of the vaporized water in the effluent from the stillcolumn in the effluent condenser apparatus. The liquid water and theliquid hydrocarbons obtained from the effluent are collected in thechamber 106 and are separated by gravity. The liquid hydrocarbons riseto the top and exit through outlet 118 and flow with the gaseouscomponents to the vacuum port 134 of the eductor 52. The liquid watersettles to the bottom and flows under the bottom 114 of the pipe 110 andup through the pipe 110. The liquid water then flows through pipe 120 tothe outlet pipe 122. A conduit 136 (FIG. 2) having a normally open motorvalve (not shown) mounted therein connects outlet pipe 122 to the inletport 126. The liquid water flows from outlet pipe 122 through conduit136 and into the chamber 108 through the inlet port 126. The chamber 108has the same vacuum as the chamber 106. When the water level in thechamber 108 reaches a predetermined high level set point, the levelcontrol apparatus (not shown) but inserted through the connection 128puts out a gas signal to open a water dump valve (not shown) and toclose the normally open motor valve (not shown) in the conduit 136. Thegas signal also energizes pressure supply port 132 to pressurize chamber108 to above atmospheric pressure and cause the liquid water to flow outof the chamber 108 through liquid water outlet port 130 and the nowopened motor valve (not shown). When the liquid water level in thechamber 108 reaches a predetermined low level, the level controlapparatus vents off the pressure, opens the motor valve in the conduit136 and closes the water dump valve. When the motor valve in the conduit136 opens, the gas under pressure flows through the inlet 126 throughthe conduit 136 and outlet pipe 122 and out through the top 112 of pipe110 into the chamber 106 and is withdrawn from the chamber 106 by thevacuum of the eductor 52 so that the vacuum pressure is equalized in thechambers 106 and 108. The liquid water then again begins to flow intothe chamber 108. The liquid water separator and removal apparatus 102 isprovided with a drain port 142 for the chamber 106 and a drain port 144for the chamber 108. Also, heating apparatus 146 is provided in theliquid water separator and removal apparatus 102.

In FIG. 6, there is illustrated a preferred embodiment of the effluentcondenser 42. This effluent condenser 202 has a hollow shell 204 havinglongitudinal fins 206 formed thereon which fins are formed from amaterial having a high coefficient of thermal conductivity. The hollowshell 204 has an inlet 208 for receiving circulating wet glycol frompiping 210 similar to piping 44 in FIG. 1. After passing through thehollow shell 204, the circulating wet glycol exits through outlet 212.An elongated tube 214 extends through the hollow shell 204 and is insealed relationship therewith. The elongated tube 214 is also providedwith a fin 216 formed thereon which fin 216 is preferably spiralled andformed from a material having a high coefficient of thermalconductivity. If desired, the fin 216 could be a plurality oflongitudinally extending fins. The elongated tube 214 has an inlet 218for receiving effluent from the still column 30 through piping 220 whichis similar to piping 46 of FIG. 1. As the effluent pass through theelongated tube 214, they are cooled and condensed into at least liquidwater, liquid hydrocarbons and uncondensed vapors containing at leastgaseous hydrocarbons which exit through outlet 222 into piping 224. Athermostat 226 is located in the outlet 222 to sense the temperature ofthe at least liquid water, liquid hydrocarbons and uncondensed vaporsleaving the effluent condenser 202 for purposes described below. Thetemperature of the liquid water, liquid hydrocarbons and uncondensedvapors flowing out of the effluent condenser 202 is preferably betweenabout 100° and 120° F.

In another embodiment of the invention, also illustrated in FIG. 6, anopen ended hollow housing 230 surrounds the effluent condenser 202 andis spaced from the fins 206. The hollow housing 230 has an enlargedportion 232 in which there is mounted a fan 234. If the temperature ofthe liquid water, liquid hydrocarbons and uncondensed vapors passingthrough the outlet 222 is greater than about 140° F., the thermostat 226functions to turn on the fan 234 to provide a forced draft over thehollow shell 204 to provide additional cooling in the effluent condenser202. The fan 234 functions to provide a sufficient cooling effect untilthe temperature in the thermostat reaches about 120° F. or less at whichtemperature, the fan 234 is turned off.

In FIG. 7, there is illustrated another embodiment of the effluentcondenser 42. This effluent condenser 240 comprises an elongated tube242 provided with a plurality of longitudinal fins 244 formed thereonwhich fins 244 are formed from a material having a high coefficient ofthermal conductivity. The elongated tube 242 has an inlet 246 connectedto the piping 220 to receive the effluent from the still column 30 ofFIG. 1. An open ended hollow housing 248 surrounds the elongated tube242 and is spaced from the fins 244. The open ended hollow housing 248has an enlarged portion 250 in which there is mounted a fan 252. Asdescribed above, as the effluent from the still column 30 passes throughthe elongated tube 242, the effluent is cooled to produce at leastliquid water, liquid hydrocarbons and uncondensed vapors which exit theelongated tube 242 through outlet 254 and into piping 224. A thermostat256 is located in the outlet 254 and measures the temperature of the atleast liquid water, liquid hydrocarbons and uncondensed vapors flowingthrough the outlet 254. If the temperature of the at least liquid water,liquid hydrocarbons and uncondensed vapors flowing through the outlet254 is greater than 140° F., the thermostat 256 functions to turn on thefan 252 to provide a forced draft over the elongated tube 242 and thefins 244. The fan 252 functions to provide a sufficient cooling effectuntil the temperature in the thermostat 256 reaches about 120° F. orless at which temperature the fan is turned off.

In FIGS. 8 and 9, there is illustrated another embodiment of the secondseparator identified in FIGS. 2-5 as the liquid water separator andremoval apparatus 102. This second separator 260 comprises a closedhollow shell 262 having spaced apart sealed baffles 264 and 266 todivide the closed hollow shell 262 into three separate chambers 268, 270and 272. The second separator has an inlet port 274 connected to thepiping 224 to receive the liquid water, the liquid hydrocarbons and theuncondensed vapors from the effluent condenser into chamber 268 wherethey are separated into a lower portion of liquid water, an intermediateportion of liquid hydrocarbons and an upper portion of uncondensedvapors. A pipe 276 is mounted in chamber 268 and has an upper open endlocated in the upper portion having the uncondensed vapors. The lowerend of the pipe 276 is connected to piping 278 connected to the vacuumport of an eductor (described more fully below). The uncondensed vaporsare drawn from the upper portion through the pipe 276 by the vacuum inthe enductor (described more fully below).

The liquid hydrocarbons are removed from the chamber 268 by suitableconventional apparatus such as that described above for removing theliquid water from the liquid water separator and removal apparatus 102described above. An outlet port 280 projects outwardly from the chamber268 through the closed hollow shell 262. As illustrated in FIG. 9, theoutlet port 280 is located below the upper open end of pipe 276. Aninlet port 282 in FIG. 8 extends through the closed hollow shell 262 andhas an opening into the chamber 270. A conduit 284 having a normallyopen motor valve (not shown) therein connects the outlet port 280 withthe inlet port 282. The liquid hydrocarbons flow through outlet port280, conduit 284 and into chamber 270 through the inlet port 282. Thechamber 270 has the same vacuum as the chamber 268. When the level ofthe liquid hydrocarbons reaches a predetermined high level set point,the level control apparatus (not shown) but inserted through theconnection 286 puts out a signal to open a liquid hydrocarbon dump valve(not shown) and to close the normally open motor valve in the conduit284. The signal also energizes gas pressure supply port 288 topressurize chamber 270 to above atmospheric pressure and cause theliquid hydrocarbons to flow out of the chamber 270 through pipe 292mounted in the chamber 270 and having a lower inlet opening and anoutlet port 292 connected to piping 294 leading to a liquid hydrocarbonstorage tank (not shown). When the liquid hydrocarbons in the chamber270 reach a predetermined low level, the level control apparatus ventsoff the pressure, opens motor control valve (not shown) in the conduit284 and closes the liquid hydrocarbon dump valve. When the motor valvein the conduit 284 opens, gas under pressure flows through the inletport 282, conduit 284 and outlet port 280 into the chamber 268 and iswithdrawn from the chamber 268 with the uncondensed vapors through thepipe 276.

The liquid water is removed from the chamber 268 by suitable apparatussuch as that described above for removing the liquid water from theliquid water separator and removal apparatus 102. An outlet port 302 inthe open ended pipe 314 projects outwardly from the chamber 268 throughthe closed hollow shell 262. As illustrated in FIG. 9, the outlet port302 is located below the outlet port 280. An inlet port 304 extendsthrough the closed hollow shell 262 and has an opening into the chamber272. A conduit 306 having a normally open motor valve (not shown)therein connects the outlet port 302 with the inlet port 304. The liquidwater flows through the lower open end of pipe 314 to the outlet port302, conduit 306 and into chamber 272 through the inlet port 304. Thechamber 272 has the same vacuum as the chamber 268. When the level ofthe liquid water reaches a predetermined high level set point, the levelcontrol apparatus (not shown) but inserted through the connection 308puts out a signal to open a normally closed liquid water dump valve (notshown) and to close the normally open motor valve in the conduit 306.The signal also energizes gas pressure supply port 310 to pressurizechamber 272 to above atmospheric pressure and cause the liquid water toflow out of the chamber 272 through outlet 312 and the now opened liquidwater dump valve mounted in the chamber 272 to a liquid water storagetank (not shown). When the liquid water in the chamber 272 reaches apredetermined low level, the level control apparatus vents off thepressure, opens motor control valve in the conduit 306 and closes theliquid water dump valve. When the motor valve in the conduit 306 opens,gas under pressure flows through the inlet port 304, conduit 306 andoutlet port 302 and out through the top of pipe 314 into the chamber 268and is withdrawn from the chamber 268 with the uncondensed vaporsthrough the pipe 276. Also, the bottom of pipe 314 is open so thatliquid water in the chamber 268 flows upwardly through the pipe 314 andthen out through the outlet port 302. The second separator 260 also hasa heated coil 316 for purposes described below. The heated coil 316 isillustrated as passing through the second separator 260 in a straightpath but the heated coil 316 could be U-shaped and makes the turn inchamber 268 and then back through chamber 272.

In FIG. 10, there is illustrated another embodiment of the inventionwherein the first separator comprises a two phase emissions separatorapparatus 320 which is used instead of the three phase emissionsseparator apparatus 16 of FIG. 1. The emissions separator apparatus 320comprises a generally cylindrical shell 322 closed at each end 324 and326 to form a pressure tight vessel which operates at about 15 PSIG. Aplurality of inlet and outlet ports project outwardly from thecylindrical shell 322. The locations of the various ports in the drawingand the following description are for illustration purposes only and maybe at different locations in an actual apparatus. As described below,the emissions separator apparatus 320 has the capacity to hold the wetglycol received from the absorber 2 of FIG. 1 and the wet glycol that iscirculated through the rest of the system and an additional amount ofwet glycol. The wet glycol from the absorber 2 of FIG. 1 flows throughpiping and enters the emissions separator apparatus 320 through inletport 328. The circulating wet glycol and the uncondensed vapors from aneductor, described below, enter the emissions separator apparatus 320through inlet port 330. In a circulating system wherein portions of thewet glycol are passed through a particulate filter, such wet glycolenters the emissions separator apparatus 320 through inlet port 332.Port 334 is provided for mounting a valve (not shown) to dump wet glycolfrom the emissions separator apparatus 320 to the coil 27 in the dryglycol storage 28 which receives and holds the hot dry glycol from thereboiler 24 as described above. A pressure relief valve (not shown) ismounted at port 338. Liquid level control apparatus (not shown) passesthrough a sealed opening 340. Gauge glasses are mounted in sealedopenings 342 and 344. A thermometer (not shown) is installed throughsealed opening 346. The circulating wet glycol passes through outletport 348 to a circulating pump as described below. A gas dryer (notshown) is mounted through sealed opening 350 in end 326. An immersiontype electric heater (not shown) is installed through sealed opening 352in end cap 324 for purposes described below.

In FIG. 11, there is illustrated a wet glycol heat exchanger 360 whichis used in the system illustrated by the block diagrams in FIG. 12. Theheat exchanger 360 is used to provide an increase in temperature to thewet glycol being circulated in the system including the emissionsseparator, the eductor and the liquid separator and removal apparatus.The heat exchanger 360 comprises finned tubes 362 and 364 open at bothends. The finned tubes 362 and 364 are joined together by a 180 degreereturn bend 366 so as to form a U-shaped structure. The tube 362 has aninlet portion 368 which may receive at least part or all of the wetglycol being circulated, as described below, and an outlet portion 370through which the heated wet glycol flows. The finned tubes 362 and 364are encased within tubes 372 and 374 which are closed at both endsaround tubes 362 and 364 to form pressure tight shells and are connectedtogether by hollow tube 376. Hot wet glycol from a heat exchanger, suchas the coil 27 of the dry glycol storage 28 of FIG. 1, enters the tube372 through inlet port 378 and flows through hollow tube 376 into tube374 to heat the wet glycol passing through tubes 362 and 364. The hotwet glycol in the tube 374 exits through outlet port 380 and movesthrough suitable piping to enter the still column 30 of FIG. 1.

The operation of the heat exchanger 360 of FIG. 11 is explained inrelationship to the block diagram in FIG. 12. Referring to FIG. 1, hotdry glycol is received in storage tank 28 from the reboiler 24. A coil27 is mounted in the storage tank 28 and receives wet glycol from eitherthe emissions separator apparatus 16 of FIG. 1 or the emissionsseparator apparatus 320 of FIG. 10 through pipe 26. The wet glycolpasses through the coil 27 so that the temperature thereof is increasedand exits therefrom and flows through pipe 382 to inlet port 378, passesover the tubes 362 and 364 in the heat exchanger 360 and exits throughoutlet port 380 into pipe 29 of FIG. 1 leading to the still column 30.As illustrated in FIG. 12, the wet glycol in fine 384 from the emissionsseparator apparatus 320 either bypasses the heat exchanger 360 throughline 386 or flows through the heat exchanger 360 through line 388. Asexplained more fully below, a control valve 390 is controlled by athermostat 392 associated with the emissions separator apparatus 320 tocontrol the amount of wet glycol flowing through the heat exchanger 360.

The operation of a gas dehydrator using the effluent condenser 202 ofFIG. 6 is illustrated in FIG. 13. Wet glycol from the absorber 2 of FIG.1 flows through pipe 394 to the inlet port 328 of the two phaseemissions separator apparatus 320. The wet glycol is collected in thetwo phase emissions separator apparatus 320 as described above so thatthere is a predetermined amount of wet glycol to be circulated and anadditional amount of wet glycol that is passed through the system toremove the water therefrom. Suitable liquid level control apparatuspasses through a sealed opening in the two phase emissions separatorapparatus 320 to control the level of the wet glycol in the two phaseemissions separator apparatus 320.

The effluent from the still column 30 of FIG. 1 flows through piping 220into the finned tube 214 in the effluent condenser 202. The circulatingwet glycol, as described above, is withdrawn from the emissionsseparator apparatus 320 as shown in FIGS. 13 and 14 through outlet 348and enters a pump 402 which circulates the wet glycol either through aparticulate filter 416 or transmission line 384 or both as describedbelow.

The wet glycol for circulation through the system is withdrawn from theemissions separator apparatus 320 through outlet 348 and enters into apump 402 which feeds the wet glycol into the line 403 at the rate ofabout 20 gallons per minute and at a pressure of between about 50-115PSIG. A normally closed switch 404 is provided in the line 403 to sensethe pressure of the wet glycol leaving the pump 402.

A loss of pressure in the line 403 would potentially decrease the vacuumbeing pulled by the eductor (described below) which could cause an overpressure condition in the reboiler 24 of FIG. 1. If the pressure in theline 403 falls below 40 PSIG, switch 404 opens. The opening of switch404 deactivates electric solenoid valve 406 which opens normally closedmotor valve 408 located upstream of the inlet port 410 on the liquidseparator and removal apparatus 260. The opening of motor valve 408vents the liquid separator and removal apparatus 260 to atmospherethrough line 409 to prevent any build up of pressure in the reboiler 24.

The pump 402 feeds wet glycol into line 403 at the rate of at least 20gallons per minute and a pressure of at least about 50 PSIG to provide asufficient flow of wet glycol through the eductor 430 (described below)and to provide side stream filtration of any wet glycol not required topower eductor 430. At point 412, line 403 is divided into line 384 and aside stream line 414 which carries any circulating wet glycol to aparticulate filter 416. A manually adjustable valve 418 controls theflow of the wet glycol through the particulate filter 416 so thatcleaned wet glycol flows back into the emissions separator apparatus 320through line 419. A valve (not shown) in the line 414 permits theclosing of line 414 so that the particulate filter 416 may be changed asnecessary. The pump 402 and the adjustable valve 418 ensure thatsufficient wet glycol is being circulated in line 384 to operate theeductor 430 so that only excess circulating wet glycol flows through theparticulate filter 416.

The wet glycol, circulated through the system of this invention asillustrated in FIGS. 12 and 13, preferably is at a temperature ofbetween about 80°-120° F. At point 420 in FIG. 12, line 384 carrying thewet glycol is split to provide for the flow of the wet glycol from line384 into either line 386 or 388. The motor valve 390, operated inresponse to the thermostat 392, controls the flow of the wet glycol intoeither line 386 or 388. When the temperature of the wet glycol flowingthrough line 384 decreases to about 90° F., the thermostat 392 graduallyopens motor valve 390 so that some of the wet glycol flows through line388 and enters the inlet port 368 of the heat exchanger 360 in an amountdependent on the opening of the valve 390. As the wet glycol passesthrough the heat exchanger 360, the temperature of the wet glycol isincreased and exits into line 389. The rest of the wet glycol from line384 flows through line 386 to the inlet port 208 of the hollow shell 204to cool the effluent in the elongated tube 214 and then leaves throughthe outlet port 212. At point 422, the wet glycol from outlet port 212joins any heated wet glycol in the line 389 and flows through line 424into the heated coil 316 in the liquid water separator and removalapparatus 260. If the thermostat 392 would fully open motor valve 390,substantially no wet glycol would flow through line 386 to the hollowshell 204. Since inlet port 208 is at a higher elevation than the inletportion of the heated coil 316, a hydrostatic head of glycol is createdbetween the inlet port 208 and the inlet portion of the heated coil 316.Therefore, the wet glycol required by the eductor 430 (described below)will preferentially flow through line 388 into the heat exchanger 360.

The circulating wet glycol leaving the heated coil 316 flows throughline 426 to the inlet port 428 of the eductor 430. As the circulatingwet glycol passes through the eductor 430, it creates a vacuum whichdraws the separated uncondensed vapors, including gaseous hydrocarbons,from the chamber 268 of the liquid separator and removal apparatus 260through piping 278. The eductor 430 also compresses the uncondensedvapors and entrains them with the wet glycol flowing through the eductor430 which then leave through outlet port 434 and flow under pressure ofabout 15 PSIG through line 436 into the emissions separator apparatus320. Check valve 438 in line 432 and check valve 440 in line 432function to prevent the pressure in the emissions separator apparatus320 from back flowing into the above-described vacuum system. The volumeof the circulating wet glycol required to power the eductor 30 is afunction of the size of the eductor 430. For a smaller dehydrator, a oneinch eductor is used and requires a circulating wet glycol volume ofapproximately 10 gallons per minute.

The operation of the dehydrator using the effluent condenser 240 of FIG.7 is illustrated in FIG. 14. As explained above, the primary differencebetween effluent condenser 240 and effluent condenser 202 is that no wetglycol is passed through effluent condenser 240. As described above, thewet glycol in line 384 reaches the point 420 in FIG. 12. When the motorvalve 390 is substantially or completely closed, most or all of the wetglycol flows through line 386 to the heating coil 316 in the liquidwater separator and removal apparatus 260. If the motor valve 390 ishalfway or completely opened by the thermostat 392, most or all of thewet glycol flows through line 388, the heat exchanger 360 and line 389until it reaches point 442 where it is combined with any wet glycolflowing from the heated coil 316 in the liquid water separator andremoval apparatus 260 to flow through line 426 into the eductor 430.Since the inlet of the heated coil 316 in the liquid water separator andremoval apparatus 260 is at a higher elevation than the inlet port 428of the eductor 430, a hydrostatic head of wet glycol is created betweenthe inlet of the heated coil 316 and the inlet port 428 of the eductor430. Therefore, any time the motor valve 390 is opened by the thermostat392, the circulating wet glycol will preferentially flow through theheat exchanger 360 into line 389. Instead of the valve 390, aconventional three way valve may be used to control the flow of thecirculating wet glycol.

Under most conditions, the heat exchanger 360 will provide enough heatto keep the wet glycol in the emissions separator apparatus 320 atdesired operating temperatures. If necessary, a conventional electricimmersion heater may be inserted into the emissions separator apparatus320 through opening 352.

In FIG. 15, there is illustrated apparatus for preventing an undesirablebuild up of a liquid hydrocarbon level in a two phase emissionsseparator apparatus 320 which has located therein a lower liquid level450 of wet glycol; an intermediate liquid level 452 of liquidhydrocarbons and an upper level 454 of hydrocarbon gases. A casing 456is mounted in the two phase emissions separator 320 and has a lowerclosed end 458 that is located to be in the lower liquid level 450 ofwet glycol and an upper open end 460 that is located in the intermediateliquid level 452 of liquid hydrocarbons. A vertical pipe 462 is mountedthrough a threaded plug 464 in the two phase emissions separatorapparatus 320 so that a lower open end 466 is located within the casing456 at a location adjacent to but spaced from the lower closed end 458between about 0.75 and 1.25 inches and preferably about 1.00 inch. Theupper open end of the vertical pipe 462 is connected to a solenoid valve468 for purposes described below. A choke nipple (not shown) on theoutlet side of the solenoid valve preferably controls the volume ofliquid hydrocarbons to be dumped to between about 1.25 and 0.50 gallonper minute and preferably about 1.0 gallon per minute.

A conventional throttling liquid level control apparatus 470 has adisplacer 472, sometimes referred to as a float, mounted in theemissions separator apparatus 320 to sense the level of the liquids inthe emissions separator apparatus 320. The throttling liquid levelcontrol apparatus 470 functions to regulate dump valve 474 which feedswet glycol to the still column 30 of the reboiler 24. Only a very smallalmost microscopic movement of the displacer 472 is required to signalthe liquid level control apparatus 470 to open or close dump valve 474.The volume of wet glycol 450 in the emissions separator apparatus 320 isgreater than the amount of wet glycol to be sent to the reboiler 24 andthe amount of wet glycol being circulated by the pump 36. In normaloperation, the wet glycol from the absorber 2 is fed into the wet glycolin the emissions separator apparatus 320 and the liquid controlapparatus 470 functions to send substantially the same amount of wetglycol to the still column 30 of the reboiler 24.

An open ended tube 476 is mounted in the emissions separator apparatus320 so that the upper open end 478 is located above the level of theliquids in the emissions separator apparatus 320 as controlled by thethrottling liquid level control apparatus 470 and is exposed to thehydrocarbon gases 454. The lower open end 480 is located adjacent to butspaced from the bottom of the emissions separator apparatus 320 whichspace, in one embodiment of the invention, preferably is about one inch.An open ended pipe 482 is mounted in the emissions separator apparatus320 so that the lower portion of the open ended pipe 482 is locatedwithin the open ended tube 476. The lower open end 484 determines theminimum level of wet glycol in the emissions separator apparatus 320.The upper open end 486 extends through a port 488 in the emissionsseparator apparatus 320 and is connected to the dump valve 474 so thatthe wet glycol 450 in the emissions separator apparatus 320 flowsthrough the lower open end 480, enters the lower open end 484 and flowsthrough the dump valve 474 to the still column 30 of the reboiler 24.

The apparatus for controlling the dumping of liquid hydrocarbons 452from the emissions separator apparatus 320 is illustrated in FIGS.15-17. A hollow tube 490 having a closed end 492 is mounted in theemissions separator apparatus 320 so that the closed end 492 is locatedin the wet glycol 450 in the emissions separator apparatus. A reedswitch (not shown) is located adjacent to but spaced from the closed end492 for a purpose described below. The upper end 494 of the hollow tube490 passes through a port 496. A wire 498 has one end connected to thereed switch (not shown) and its other end connected to a control box 500for operating the solenoid valve 468. A float 502, weighted to float onthe wet glycol 450 in the emissions separator apparatus 320, is mountedfor sliding movement over the tube 490. The float 502 has magneticapparatus (not shown) mounted therein to operate the reed switch in thehollow tube 490 as described below.

The operation of the apparatus for the dumping of the liquidhydrocarbons 452 from the emissions separator apparatus 320 isillustrated in FIGS. 15-16. The commencement of the operation of theapparatus is illustrated in FIG. 16. The wet glycol 450 in the emissionsseparator apparatus 320 is at its highest level and there are no liquidhydrocarbons 452 in the emissions separator apparatus 320. Thethrottling liquid level control apparatus 470 has opened dump valve 474so that, as wet glycol from the absorber 2 enters the emissionsseparator apparatus 320, a similar amount of wet glycol is dumpedthrough the dump valve 474. As the apparatus continues to operate smallamounts of liquid hydrocarbons 452 will be deposited in the emissionsseparator apparatus 320. The liquid hydrocarbons 452 can result fromthose in the wet glycol coming from the absorber, from those coming withthe wet glycol from the eductor and those condensed from the gaseoushydrocarbons 454 in the emissions separator apparatus.

Over a period of time, which may be months or a year or longer, thebuild up of the liquid hydrocarbons 452 will continue until they reachthe level illustrated in FIG. 15. The float 502 floating on the top ofthe wet glycol 450 in the emissions separator apparatus 320 has moveddownwardly, as illustrated in FIG. 15, to a position to trip the reedswitch in the hollow tube 490 to send a signal to open solenoid valve468 so that liquid hydrocarbons 452 will begin to flow through pipe 462out of the emissions separator apparatus 320. The rate of flow of theliquid hydrocarbons 452 is greater than the rate of flow of wet glycolfrom the absorber 2 into the emissions separator apparatus 320.Therefore, the level of the liquids in the emissions separator apparatus320 will fall causing liquid level control apparatus 470 to close dumpvalve 474 so that no wet glycol 450 is being dumped to the reboiler 24.The liquid hydrocarbons 452 in the emissions separator apparatus 320will be continued to be dumped through pipe 462 until sufficient wetglycol from the absorber 2 has raised the level of the wet glycol 450 inthe emissions separator apparatus 320 a sufficient amount so that thefloat 502 will function to open the reed switch and close the solenoidvalve 468. The throttling liquid level control apparatus 470 willcontinue to keep the dump valve 474 closed and will only open the dumpvalve 474 once the total level of the liquids, i.e., the liquidhydrocarbons 452 and the wet glycol 450, reach the level illustrated inFIGS. 16 and 17. If the level of the wet glycol 450 does not cause thefloat 502 to close the solenoid valve 468 until after the level of theliquid hydrocarbons 452 have reached the upper open end 460 only a smallquantity of gaseous hydrocarbons will flow through the solenoid valve468 until the level of the wet glycol 450 reaches the required level. Asa safety measure, a second reed switch (not shown) may be located in thehollow tube 490 to ensure that the solenoid valve 468 is closed in theevent of a failure of the first reed switch to close the solenoid valve.A pipe 504 connects the solenoid valve 468 to suitable collectionapparatus for the storage of liquid hydrocarbons. If the liquidhydrocarbons 452 were not removed from the emissions separator apparatus320, it is possible that the upper level of the wet glycol in theemissions separator apparatus 320 would fall below the lower open end480 so that liquid hydrocarbons 452 would flow through pipe 482 and dumpvalve 474 to the reboiler 24 to possibly cause disastrous results. Theseresults can also happen when the emissions separator apparatus has weirapparatus for the removal of the liquid hydrocarbons. It is noted thatinitially a small amount of the wet glycol will be collected in thecasing 456 and will flow through the open solenoid valve 468.

A liquid gauge 510 is installed in the emissions separator apparatus 320to show the level of the liquid hydrocarbons 452 in the emissionsseparator apparatus 320. One open end 512 is installed so that it islocated below the top level of the liquids in the emissions separatorapparatus 320. The lower open end 514 is located so that it will alwaysbe exposed to the wet glycol 450 in the emissions separator apparatus452. The liquid gauge will contain a mark (not shown) indicating thatthe level of the wet glycol 450 should not be below such mark.

The preferred operation of the apparatus schematically illustrated inFIGS. 15-17 is as follows. In FIG. 16, there is illustrated the locationof the various parts as the apparatus starts to operate. The float 502is at the top of the wet glycol 450 in the emissions separator apparatus320. The upper open end 460 is spaced a distance of between about 0.33and 0.60 inch and preferably about 0.50 inch below the level of the wetglycol 450 as indicated by the float 502. This location of the upperopen end 460 is a first predetermined level. The displacer 472 hassignalled the liquid level control apparatus 470 to open dump valve 474so that the amount of the wet glycol being transferred to the stillcolumn 30 is substantially equal to the amount of the wet glycol beingreceived from the absorber 2 by the emissions separator apparatus.

As described above, liquid hydrocarbons 452 begin to be deposited in theemissions separator apparatus 320 until the depth of the liquidhydrocarbons 452 has reached between about 3.75 and 4.25 inches andpreferable about 4.00 inches. As illustrated in FIG. 15, the float 502,which is floating on the top of the wet glycol 450, is now at a distancebelow the upper open end 460. This location of the float 502 is a secondpredetermined level. At this second predetermined level, the float 502operates the reed switch (not shown) in the tube 490 to close a circuitto open solenoid valve 468 so that the dumping of the liquidhydrocarbons 452 from the emissions separator apparatus 320 commences.The dumping of the liquid hydrocarbons 452 from the emissions separatorapparatus 320 is at a rate greater than the rate at which wet glycol isreceived from the absorber 2 so that the liquid level in the emissionsseparator apparatus 320 is being lowered. When the displacer 472 sensesa change in the liquid level in the emissions separator apparatus 320, athird predetermined level, the displacer 472 signals the liquid levelcontrol apparatus 470 to close the dump valve 474 so that no wet glycolis being transferred to the still column 30. At this time, the wetglycol being received from the absorber 2 raises the level of wet glycolin the emissions separator apparatus 320. Therefore, the float 502begins to move upwardly. When the float 502 reaches a level between thefirst and second predetermined levels, which level is a fourthpredetermined level, the reed switch in the tube 490 is opened and thesolenoid valve 468 is closed to stop the dumping of the liquidhydrocarbons 452. The level of the wet glycol continues to rise until itreaches the level indicated in FIG. 17. The liquid level in theemissions separator apparatus 320 continues to rise until it has reacheda level at which the displacer 472 signals the liquid level control 470to open dump valve 474 so that wet glycol is transferred to the stillcolumn 30 at substantially the same rate as the wet glycol is beingreceived from the absorber 2.

The dimensions cited above may be varied depending on the size of thenatural gas dehydrator.

While illustrative and presently preferred embodiments of the inventionhave been described in detail herein, it is to be understood that theinventive concepts may be otherwise variously embodied and employed andthat the appended claims are intended to be construed to include suchvariations except insofar as limited by the prior art.

What is claimed is:
 1. In apparatus for use with a natural gasdehydrator wherein a supply of natural gas is fed into an absorberwherein it is subjected to dry glycol to remove undesirable materials,including water, therefrom so that the dry glycol is changed into wetglycol that is removed from the absorber, the method comprising:providing first separator apparatus containing a supply of wet glycoland located to receive wet glycol from said absorber; transferring atleast portions of said wet glycol in said first separator apparatus to astill column of a reboiler apparatus using a first transfer apparatus sothat said transferred portions of said wet glycol can be changed to atleast dry glycol and effluent; transferring said effluent from saidstill column to condenser apparatus using a second transfer apparatus;converting said effluent into at least liquids and uncondensed vapors insaid condenser apparatus; providing second separator apparatus;transferring said liquids and said uncondensed vapors to said secondseparator apparatus using a third transfer apparatus; circulating otherportions of said wet glycol from said first separator apparatus in acirculatory path and returning said other portions of said wet glycol tosaid first separator apparatus; separating at least most of saiduncondensed vapors from said liquids in said second separator apparatus;and entraining and compressing most of said uncondensed vapors with saidcirculating other portions of said wet glycol to be returned therewithto said first separator apparatus.
 2. A method as in claim 1 and furthercomprising: producing a force by locating force producing apparatushaving an inlet port and an outlet port in said circulatory path so thatsaid other portions of said wet glycol pass through said force producingapparatus to produce said force; using said force to transfer at leastsaid uncondensed vapors from said second separator apparatus to saidforce producing apparatus using a fourth transfer apparatus; andentraining and compressing said at least said uncondensed vapors withsaid other portions of said wet glycol in said force producing apparatusand returning said entrained uncondensed vapors and said other portionsof said wet glycol to said first separator apparatus.
 3. A method as inclaim 2 wherein said force is produced by a method comprising: locatingan eductor having said inlet port, said outlet port and a vacuum port insaid circulatory path so that said other portions of said wet glycolpass through said eductor to create a vacuum therein; and connecting atleast a portion of said fourth transfer apparatus to said vacuum port sothat said vacuum draws substantially all of said uncondensed vapors fromsaid second separator apparatus so that said substantially all ofuncondensed vapors drawn into said eductor are entrained and compressedwith said other portions of said wet glycol.
 4. A method as in claim 2wherein said effluent is converted by a method comprising: flowing saidother portions of said wet glycol through a hollow shell located in saidcirculatory path; and passing said effluent through a tube in sealedengagement with and extending through said hollow shell so that saideffluent is converted into liquid water, liquid hydrocarbons anduncondensed vapors.
 5. A method as in claim 4 and further comprising:dividing said circulatory path into a first path and a second path;combining said first path and said second path back into saidcirculatory path; locating heat exchanger apparatus in said first pathso that any portion of said other portions of wet glycol in said firstpath passes through said heat exchanger apparatus; raising thetemperature of said any portion of said other portions of wet glycol asthey pass through said heat exchanger apparatus; controlling the flow ofsaid other portions of wet glycol through either said first path or saidsecond path; passing said at least another portion of said otherportions of said wet glycol in said second path through said condenserapparatus; and using a first thermostat apparatus to control the flow ofany portion of said other portions of said wet glycol through eithersaid first path or said second path or both.
 6. A method as in claim 5and further comprising: surrounding said condenser apparatus with anopen ended housing so that a circular space exists between said housingand said condenser apparatus; flowing a cooling fluid through said spaceto cool further said effluent in said tube; and controlling theoperation of said cooling fluid by second thermostat apparatus.
 7. Amethod as in claim 2 wherein said effluent is converted by a methodcomprising: flowing said other portions of said wet glycol flow througha hollow shell located in said circulatory path; passing said effluentthrough a tube in sealed engagement with and extending through saidhollow shell so that said effluent is converted into liquid water,liquid hydrocarbons and uncondensed vapors; and transferring said otherportions of said wet glycol from said condenser apparatus to said forceproducing apparatus using fifth transfer apparatus extending betweensaid condenser and said force producing apparatus.
 8. A method as inclaim 2 wherein said effluent is converted by a method comprising:passing said effluent through an elongated tube having an inletconnected to said second transfer apparatus and an outlet connected tosaid third transfer apparatus; surrounding said elongated tube with anopen ended housing; passing a fluid through said open ended housing tocool said effluent in said elongated tube; and controlling the operationfor passing a fluid through said open ended housing by first thermostatapparatus.
 9. A method as in claim 8 and further comprising: dividingsaid circulatory path into a first path and a second path; combiningsaid first path and said second path back into said circulatory path;locating heat exchanger apparatus in said first path so that any portionof said other portions of said wet glycol in said first path passesthrough said heat exchanger apparatus; raising the temperature of saidat least part of said other portions of said wet glycol as they passthrough said heat exchanger apparatus; controlling the flow of saidother portions of wet glycol through either said first path or saidsecond path; and using second thermostat apparatus to control the flowof said other portions of said wet glycol through either said first pathor said second path or both.
 10. A method as in claim 2 wherein:providing said reboiler with a still column; transferring dry glycolfrom said reboiler to storage tank apparatus using heat exchangerapparatus located therein; and passing said portion of said wet glycolin said first transfer apparatus through said heat exchanger apparatusin said storage tank to raise the temperature of said portions of wetglycol prior to the transfer thereof to said still column.
 11. A methodas in claim 2 wherein said first separator apparatus also containstherein gaseous hydrocarbons and liquid hydrocarbons so that the gaseoushydrocarbons are located in an upper portion thereof, the liquidhydrocarbons are located in an intermediate portion thereof and the wetglycol is located in a lower portion thereof which method furthercomprises: sensing the level of said liquids in said first separatorapparatus to control the amount of said wet glycol being transferred tosaid still column; sensing the level of said wet glycol in said firstseparator apparatus; locating dumping apparatus for dumping at leastportions of the liquid hydrocarbons from said first separator apparatusso that an inlet portion of said dumping apparatus is at a firstpredetermined level in said first separator apparatus and wherein saiddumping apparatus is normally in a closed position; opening said dumpingapparatus when said wet glycol in said first separator apparatus hasreached a second predetermined level which is below said firstpredetermined level; stopping the transfer of said wet glycol from saidfirst separator apparatus to said still column when said level of saidliquids in said first separator apparatus reaches a third predeterminedlevel which is located above said first predetermined level; and closingsaid dumping apparatus when said level of said wet glycol in said firstseparator apparatus reaches a fourth predetermined level which isbetween said first and second predetermined levels.
 12. A method as inclaim 11 and further comprising: restarting said transfer of said wetglycol from said first separator apparatus to said still column so thatsaid level of said liquids in said first separator apparatus hasreturned to its original level.
 13. Apparatus for use with a natural gasdehydrator wherein a supply of natural gas is fed into an absorberwherein it is subjected to dry glycol to remove undesirable materials,including water, therefrom so that the dry glycol is changed into wetglycol that is removed from the absorber comprising: first separatorapparatus containing at least a supply of wet glycol and located toreceive wet glycol from said absorber; reboiler apparatus having a stillcolumn for converting wet glycol to dry glycol and effluent; firsttransfer apparatus for transferring at least portions of said wet glycolin said first separator apparatus to said still column of said reboilerapparatus; second transfer apparatus for transferring said effluent fromsaid reboiler to condenser apparatus; said condenser apparatusconverting said effluent into at least liquids and uncondensed vapors;second separator apparatus; third transfer apparatus for transferringsaid liquids and said uncondensed vapors to said second separatorapparatus; said second separator apparatus separating at least saiduncondensed vapors from said liquids; circulating apparatus for removingother portions of said wet glycol from said first separator apparatus,moving said other portions of said wet glycol in a circulatory path andreturning said other portions of said wet glycol to said first separatorapparatus; force producing apparatus located in said circulatory pathand cooperating with said other portions of said wet glycol to produce aforce; fourth transfer apparatus extending between said force producingapparatus and said second separator apparatus to transfer at leastsubstantially all of said uncondensed vapors from said second separatorapparatus to said force producing apparatus; and said force producingapparatus entraining said at least substantially all of said uncondensedvapors with said other portions of said wet glycol to be returnedtherewith to said first separator apparatus.
 14. Apparatus in claim 13wherein said force producing apparatus comprises: an eductor having aninlet port, an outlet port and a vacuum port; said eductor located insaid circulatory path so that said other portions of said wet glycolpass through said eductor to create a vacuum therein; and said fourthtransfer apparatus having at least a portion thereof connected to saidvacuum port so that said vacuum draws substantially all of saiduncondensed vapors from said second separator apparatus.
 15. Apparatusas in claim 13 wherein said condenser comprises: an elongated hollowshell having an inlet port and an outlet port and connected in saidcirculatory path so that said other portions of said wet glycol flowthrough said hollow shell; at least one tube in sealed engagement withand extending through said hollow shell and having an inlet and anoutlet and connected to said second and third transfer apparatus so thatsaid effluent passes through said at least one tube and is convertedinto liquid water, liquid hydrocarbons and said uncondensed vapors. 16.Apparatus as in claim 15 and further comprises: dividing apparatus fordividing said circulatory path into a first path and a second path;combining apparatus for combining said first path and said second pathback into said circulatory path; heat exchanger apparatus located insaid first path so that any portion of said other portions of wet glycolin said first path passes through said heat exchanger apparatus; saidheat exchanger apparatus raising the temperature of said any portion ofsaid other portions of wet glycol passing therethrough; controlapparatus for controlling the flow of said other portions of wet glycolthrough said first path or said second path; said second path passingthrough said condenser; and first thermostat apparatus for operatingsaid control apparatus.
 17. Apparatus as in claim 16 and furthercomprising: an open ended housing surrounding said condenser; coolingapparatus located in said open ended housing to cool said effluent insaid at least one tube; and apparatus for controlling the operation ofsaid cooling apparatus.
 18. Apparatus as in claim 13 wherein: saidportions of said wet glycol being transferred in said first transferapparatus are in an amount substantially equal to the amount of wetglycol received by said first separator apparatus from said absorber.19. Apparatus as in claim 13 wherein said condenser comprises: at leastone elongated tube having an inlet connected to said second transferapparatus to receive said effluent and an outlet connected to said thirdtransfer apparatus; an open ended housing surrounding said elongatedtube; cooling apparatus located in said open ended housing to cool saideffluent in said elongated tube; and first thermostat apparatus forcontrolling the operation of said cooling apparatus.
 20. Apparatus as inclaim 19 and further comprising: dividing apparatus for dividing saidcirculatory path into a first path and a second path; combiningapparatus for combining said first path and said second path back intosaid circulatory path; heat exchanger apparatus located in said firstpath so that any portion of said other portions of said wet glycol insaid first path passes through said heat exchanger apparatus; said heatexchanger apparatus raising the temperature of said any portion of saidother portions of said wet glycol passing therethrough; controlapparatus for controlling the flow of said other portions of wet glycolthrough said first path or said second path; and second thermostatapparatus for operating said control apparatus.
 21. Apparatus as inclaim 13 and further comprising: said first separator apparatus alsocontaining gaseous hydrocarbons and liquid hydrocarbons so that saidfirst separator apparatus has at least an upper portion having saidhydrocarbon gases located therein, an intermediate portion having saidliquid hydrocarbons located therein and a lower portion having said wetglycol located therein; liquid level control apparatus in said firstseparator apparatus for controlling the amount of said at least portionsof said wet glycol being transferred by said first transfer apparatus;wet glycol level control apparatus in said first separator apparatus forsensing the level of said wet glycol in said first separator apparatus;dumping apparatus associated with said first separator apparatus fordumping at least portions of said liquid hydrocarbons from said firstseparator apparatus; said dumping apparatus having valve apparatus formovement between an opened and a closed position; and control apparatusassociated with said glycol level control apparatus and said dumpingapparatus for moving said valve apparatus to said opened or said closedposition when said wet glycol level control apparatus is atpredetermined levels.
 22. Apparatus as in claim 21 wherein said liquidlevel control apparatus comprises: at least a portion of said dumpingapparatus comprises a solenoid valve; a hollow tube mounted on saidfirst separator apparatus and having a lower end portion located belowsaid predetermined levels; a control switch located in said hollow tubein an electric circuit with said solenoid valve and movable between anopened and a closed position; a float mounted for sliding movement oversaid hollow tube; said float having a weight so that it will float onsaid wet glycol; and switch control apparatus in said float for movingsaid control switch between said opened or closed position. 23.Apparatus for use with a natural gas dehydrator wherein a supply ofnatural gas is fed into an absorber wherein it is subjected to dryglycol to remove undesirable materials, including water, therefrom sothat the dry glycol is changed into wet glycol that is removed from theabsorber comprising: first separator apparatus containing a supply ofwet glycol and located to receive wet glycol from said absorber;reboiler apparatus having a still column for converting wet glycol todry glycol and effluent; first transfer apparatus for transferring atleast portions of said wet glycol in said first separator apparatus tosaid still column of said reboiler apparatus; second transfer apparatusfor transferring said effluent from said reboiler to condenserapparatus; said condenser apparatus converting said effluent into atleast liquids and uncondensed vapors; second separator apparatus; thirdtransfer apparatus for transferring said liquids and said uncondensedvapors to said second separator apparatus; circulating apparatus forremoving other portions of said wet glycol from said first separatorapparatus, moving said other portions of said wet glycol in acirculatory path and returning said other portions of said wet glycol tosaid first separator apparatus; said second separator apparatusseparating at least most of said uncondensed vapors from said liquids;and fourth transfer apparatus for entraining said at least most of saiduncondensed vapors with said circulating other portions of said wetglycol to be returned therewith to said first separator apparatus. 24.Apparatus as in claim 23 wherein: storage tank apparatus for receivingdry glycol from said reboiler and having a heat exchanger locatedtherein; said at least portions of said wet glycol in said firsttransfer apparatus being in an amount substantially equal to the amountof wet glycol received from said absorber; and said at least portions ofsaid wet glycol in said first transfer apparatus passing through saidheat exchanger in said storage tank to raise the temperature of saidportion of wet glycol prior to the transfer thereof to said stillcolumn.